Preheat oven to 400 degrees F.

Bring rice and water to a boil in a medium saucepan. Reduce heat to low, cover, and simmer at the lowest bubble until the water is absorbed and the rice is tender, 30 to 40 minutes. Remove from the heat and let stand, covered, for 10 minutes.

Meanwhile, cut eggplants in half lengthwise and score the cut sides in a deep criss-cross pattern, almost to but not cutting through the skin. Brush the cut sides generously with 2 tablespoons plus 2 teaspoons oil. Brush the skin sides lightly with 1 teaspoon oil. Place the eggplants cut-side down on a baking sheet. Bake for 15 minutes. Flip the eggplants and bake until soft, 15 to 20 minutes more. Remove and set aside. Reduce oven temperature to 350 degrees .

Meanwhile, make the filling: Heat the remaining 1 tablespoon oil in a large skillet over medium heat and add onion. Sprinkle with 1/2 teaspoon salt and cook, stirring, until the onion starts to soften, 3 to 5 minutes. Add garlic and ginger and cook, stirring, for 1 minute more. Add bison, paprika, cumin, coriander, turmeric, garam masala and cayenne to taste; cook, stirring and breaking up with a wooden spoon, until the bison is coated with spices and no longer pink, 4 to 6 minutes. Stir in tomato paste. Remove from heat.

When the eggplants are cool enough to handle, scoop out the pulp, making sure not to tear the skin. It's best to leave about a 1/4- to 1/2-inch layer of pulp attached to the skin. Coarsely chop the scooped-out pulp and add to the meat mixture. Stir until well combined. Stir in the cooked rice and season with the remaining 1 teaspoon salt and pepper. Stuff each eggplant half with equal amounts of the filling.

Return the stuffed eggplant to the baking sheet. Bake until heated through, about 20 minutes.

Note: Garam masala is a blend of spices used in Indian cooking, usually including cardamom, black pepper, cloves, nutmeg, fennel, cumin and coriander. Garam masala is available in the spice section of most supermarkets.

MAKE AHEAD TIP: Prepare through Step 5. Cover and refrigerate for up to 1 day. To serve, bake at 350 degrees F until heated through, about 30 minutes.